Not Applicable
1. Field of the Invention
The invention relates to rotary power devices, and more particularly to internal combustion engines, pumps, compressors, fluid-driven motors, and throttling devices in which the rotor includes at least two diametrically opposed pivoting pistons.
2. Background Information
This invention relates to a rotary power device with pivotable swingable pistons, such devices are characterized in having pistons or vanes that execute angular reciprocating movement within chambers in a rotating member and that engage a cam track. Examples of rotary devices of the above type can be found in U.S. Pat. No. 4,038,948 to Blackwood, U.S. Pat. No. 3,986,483 to Larson, and U.S. Pat. No. 3,788,286 to Brewer. These types of devices can function as internal combustion engines in which gas is initially entrapped within a rotor chamber as a piston swings outward towards a cam surface receding from the rotor and is then compressed when the piston swings inward as the cam surface approaches the rotor. The compressed gases ignite at minimum volume and the ignited gases exert a force on the outwardly swinging piston which, in turn, exert a force through roller cam followers on the relatively inclined cam track, the reaction to which provides the necessary torque to rotate the rotor Although such power devices have been proven to be theoretically functional, they characterized in some respects with complexities associated with cam arrangement, piston shape, and inlet and outlet arrangements, all of which make them costly to manufacture, assemble, and maintain.
A pivoting piston rotary power device of the invention comprises a stator and a rotor. The preferred stator includes a tubular external stator portion defining an internal volume having an elliptical cross-section and formed by a combination of tubular middle portion, a front end portion and a back end portion. The front end portion has a central throughhole for receiving a shaft and the tubular middle portion has at least one elliptical cam track disposed on its inner surface. There is also an internal cylindrical stator portion projecting from the back end wall portion into the internal volume along an axis of the device. The preferred internal stator portion has a plurality of passageways formed in it, each of which comprises a channel parallel to the axis that communicates with at least one respective radial port formed in a periphery of the internal stator. The rotor comprises a shaft that extends along the axis of the device and that is journaled within the central throughhole in the front end portion of the stator. The rotor also comprises a cylindrical block having a central cylindrical bore for receiving the internal stator. The block is rotatable within that portion of the internal volume lying between the internal stator portion and the external stator portion. The block further comprises at least one circular array of a selected number of working compartments equi-angularily spaced apart about the axis of the device, each of the working compartments define a respective sector of a respective cylinder having a respective cylinder axis disposed parallel to the axis of the device. Moreover, each compartment is open to the peripheral surface of the block and has a radially inwardly directed opening that communicates with the central cylindrical bore. In addition, the device comprises the selected number of pivoting piston assemblies, each of which is received in a respective working compartment and each of which has a respective pivot axis coinciding with the respective cylinder axis of the working compartment in which it is received. Each piston assembly also comprises a roller cam follower for engaging a cam track on the inner wall of the middle portion of the external stator.
One object of the present invention is to provide an improved swinging piston rotary power device that can overcome the problems presently encountered in such class of rotary engines.
Another object of the invention is to provide a rotary power device light in weight, small in size and having a minimum number of parts.
Another object of the invention is to provide a family of rotary power devices that can be easily converted from one type to another, such as a pump, compressor, hydraulic motor, fluid driven pump or compressor, by a simple modification or replacement of a central stationary member and/or cam.
Another object of the invention is to provide a rotary power device characterized by reduced noise and vibration.
These and other objects and advantages of the present invention will be apparent from the following detailed description and the appended claims.
Although it is believed that the foregoing recital of features and advantages may be of use to one who is skilled in the art and who wishes to learn how to practice the invention, it will be recognized that the foregoing recital is not intended to list all of the features and advantages. Moreover, it may be noted that various embodiments of the invention may provide various combinations of the hereinbefore recited features and advantages of the invention, and that less than all of the recited features and advantages may be provided by some embodiments.